Join Date: Jul 2013
Location: Gainesville, FL
Stop using pH down, there's just no reason to use it...no need to be messing with pH at all in fact, especially at 7.6 which is perfectly fine for most every captive bred fish (I've kept lots of fish with more alkaline pHs). By adding temporary buffers you're not going to be achieving any sort of pH balance, especially if you don't know the rest of the water chemistry.
I've seen people go anywhere from 6-12 hours, I usually shoot for 8-10 but there wont be an exact number.